[ogg-dev] How Ogg mappings translate into the codecs parameter in Ogg media types

Ivo Emanuel Gonçalves justivo at gmail.com
Sat May 24 10:07:09 PDT 2008

On 5/24/08, Ralph Giles <giles at xiph.org> wrote:
> It's supposed to be finalized though there many be some granulepos
> issues still in current implementations. I don't expect the BBCD\0
> magic to change.


> OggMNG defines the following magics:
> char[8]: "\211PNG\r\n\032\n" png
> char[8]: "\212MNG\r\n\032\n" mng
> char[8]: "\213JNG\r\n\032\n" jng

Ah, yes, I had forgotten about image encapsulation!  Doesn't OggSpots
also cover standard JPEG?  Should we add it, too?

> Are the 'Codecs Parameter' values from a different namespace from the
> media-types? Do we define a mapping where there is one, e.g. vorbis
> is audio/vorbis?

If I understand your question correctly, the answer is yes and no.  It
is part of the media types regardless of namespace, but it's just a
string to describe each contained codec not a specific media type like
what is used in Skeleton.

Here's an example: video/ogg; codecs="theora, vorbis, kate"

> And there's OggY4M which uses char[9]: "YUV4MPEG2" but that's in no
> way finalized.

So this shouldn't be added, right?


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